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Establishing a basis for ecosystem management in the western Indian Ocean

- Vousden, David, Scott, Lucy E P, Sauer, Warwick H H, Bornman, T G, Ngoile, M, Stapley, J, Lutjeharms, Johan R E

Authors: Vousden, David , Scott, Lucy E P , Sauer, Warwick H H , Bornman, T G , Ngoile, M , Stapley, J , Lutjeharms, Johan R E
Date: 2008
Language: English
Type: Article
Identifier: vital:6774 , http://hdl.handle.net/10962/d1008081
Description: An ambitious multinational programme, with generous funding for an initial five years, aims to provide understanding of marine resources for the benefit of impoverished island and coastal populations in a much-neglected ocean region.
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Date Issued: 2008

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Guidelines for Constructing Robust Discrete-Time Computer Network Simulations

- Richter, John, Irwin, Barry V W

Authors: Richter, John , Irwin, Barry V W
Date: 2008
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/429896 , vital:72649 , https://doi.org/10.1007/978-1-4020-8737-0_69
Description: Developing network simulations is a complex task that is often per-formed in research and testing. The components required to build a network simulator are common to many solutions. In order to expedite further simulation development, these components have been outlined and detailed in this paper. The process for generating and using these components is then detailed, and an example of a simulator that has been implemented using this system, is detailed
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Date Issued: 2008

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Phosphorescence of orthopaedic–grade ultra high molecular weight polyethylene

- Chithambo, Makaiko L

Authors: Chithambo, Makaiko L
Date: 2008
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/125617 , vital:35801 , https://doi.10.1002/pssc.200776802
Description: Isothermal luminescence decay curves have been measured from orthopaedic–standard ultra high molecular weight polyethylene between 35 and 70 ˚C on the rising edge of the main glow peak at 70 ˚C. Preparatory peak-shape analysis of the temperature-resolved glow peak at 70 ˚C measured at 1 ˚C s–1 gave a geometrical factor close to 0.5 suggestive of second order kinetics for both the isothermal and thermally stimulated luminescence. The results of analysis of the phosphorescence of transformed monotonic-to-peak isothermal decay curves are also second order, as is the conclusion from thermoluminescence glow-curve de-convolution. All methods of analysis give an activation energy of about 0.7 eV.
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Date Issued: 2008

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Prototyping a p2p sip user agent with support for multiple overlays

- Tsietsi, Mosiuoa, Terzoli, Alfredo, Wells, George C

Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
Date: 2008
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/430858 , vital:72722 , 10.1109/PERCOM.2008.102
Description: This paper describes a systematic approach to provide support at the user agent level for peer-to-peer based multimedia communications us-ing SIP (session initiation protocol). In a society that is becoming in-creasingly mobile, the advantages of engaging in interactive sessions without relying on central servers or infrastructure are clear. Yet, cur-rently many user agents and devices have little support for peer-to-peer communications. In this paper, we motivate for the use of structured peer-to-peer protocols called DHTs, as a foundation for a peer-to-peer layer. We introduce the concept of "DHTplug-ins" which assist in ab-stracting the interface between the higher level application and the pro-prietary APIs exposed by the underlying DHTs, allowing us to manipu-late user agents with peer-to-peer logic. This embeddable-DHT concept allows these user agents to use different DHTs with one common inter-face and participate in multiple overlays. We show how an open source SIP user agent was thus modified and how realtime communications were supported.
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Date Issued: 2008

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The eggs of Afronurus LESTAGE, 1924 (Ephemeroptera: Heptageniidae): a cue for phylogenetic relationships

- Belfiore, Carlo, Barber-James, Helen M, Gaino, Elda

Authors: Belfiore, Carlo , Barber-James, Helen M , Gaino, Elda
Date: 2008
Identifier: vital:7004 , http://hdl.handle.net/10962/d1008363
Description: Scanning electron microscopy (SEM) investigation carried out on the eggs of Afronurus scotti, A. harrisoni, A. peringueyi, and A. ugandanus, has provided some chorionic details useful for a comparison between these species. In all the species, the egg chorion is decorated with sparse granules and shows two kinds of knob-terminated coiled threads (KCTs). The first kind is represented by small KCTs (5-7 ?m in diameter) densely concentrated at each egg pole; the second kind encompasses large KCTs (60- 80 ?m in length) situated equatorially. The micropyle has an oval to round sperm guide (15-20 ?m long; 12- 18 ?m wide), and a well-defined rim. The polar KCTs expand towards the equatorial KCTs in A. scotti, A. harrisoni, and A. peringueyi, but in A. ugandanus there is a large clear area between polar and equatorial KCTs. A chorionic pattern very close to that of these Afronurus species is shared only by species belonging to the Asiatic genus Cinygmina. In addition, examination of the labrum of the nymphs belonging to both genera, indicates a very similar morphology, in the curved sclerification in the basal region of the labrum, a feature that contrasts with the almost straight shape presented by other heptageniid genera (e.g. Electrogena species). Egg and labrum characteristics are advocated to hypothesise a close phylogenetic relationship between the South-African Afronurus and the Asiatic Cinygmina genera.
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Date Issued: 2008

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The Guild comes of age! Peals and quarters at South African Guild meetings, 1988-2008. Part 1

- Lewis, Colin A

Authors: Lewis, Colin A
Date: 2008
Language: English
Type: Article
Identifier: vital:6187 , http://hdl.handle.net/10962/d1012386
Description: The founding meeting of the South African Guild was held in Grahamstown during the first weekend of July 1988. Dedication of the bells and new frame at Grahamstown cathedral marked the completion of the first Guild project to ensure that all rings of bells in South Africa were in good condition. This first part of the article takes us up to the completion of the Grahamstown restoration. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
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Date Issued: 2008

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Anaerobic digestion of fungally pre-treated wine distillery wastewater

- Melamane, Xolisa L, Tandlich, Roman, Burgess, Jo E

Authors: Melamane, Xolisa L , Tandlich, Roman , Burgess, Jo E
Date: 2007
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/71740 , vital:29932 , https://doi.org/10.5897/AJB2007.000-2305
Description: The combination of fungal pre-treatment with Trametes pubescens and anaerobic digestion were tested for the removal of chemical oxygen demand (COD) and phenolic compounds from wine distillery wastewater. The COD removal efficiency after fungal pre-treatment reached 53.3%. During digestion, pH buffering was achieved using CaCO3 and K2HPO4. This provided a stable environment inside digester for efficient and time-independent COD removal. The total COD removal efficiency reached 99.5%, and the system proved able to eliminate shock COD loads, as indicated by the concentrations of sludge and volatile fatty acids. Complex changes of phenolic compounds are suspected in anaerobic digestion system, and are investigated further.
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Date Issued: 2007

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Comparison of the direct enzyme assay method with the membrane filtration technique in the quantification and monitoring of microbial indicator organisms - seasonal variations in the activities of coliforms and E.coli, temperature and pH

- Wutor, V C, Togo, C A, Pletschke, Brett I

Authors: Wutor, V C , Togo, C A , Pletschke, Brett I
Date: 2007
Language: English
Type: Article
Identifier: vital:6479 , http://hdl.handle.net/10962/d1006241
Description: The aim of this project was to monitor variations and relationships between coliform and E. coli counts, the activities of their marker enzymes GAL and GUD, and temperature and pH over a period of 12 months in river samples obtained from the Eastern Cape, South Africa. Several polluted water samples were collected for direct coliform β-D-galactosidase (B-GAL) and Escherichia coli β-D-glucuronidase (B-GUD) assays and the membrane filtration technique. While all the samples showed enzyme activities, not all exhibited growth on CM1046 media. Variation in B-GAL activity (40%) was observed between November (highest activity month) and May (lowest activity month). The highest and lowest B-GUD activities were observed in the months of September and May/June, respectively. The sensitivity of the spectrophotometric assay method was indicated by a limit of detection (LOD) of 1 coliform forming unit (CFU)/100 mℓ and 2 CFU/100 mℓ for coliforms and E. coli, respectively. There was a significant (P < 0.05) positive correlation between E. coli counts and GUD activity (R2 = 0.8909). A correlation of R2 = 0.9151 was also observed between total coliforms and B-GAL activity, even though the CFUs were not evenly distributed. Direct enzyme assays were also shown to be more sensitive than the membrane filtration (MF) technique.
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Date Issued: 2007

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South African research in the hydrological sciences : 2003 -2006 : IUGG report

- Hughes, Denis A

Authors: Hughes, Denis A
Date: 2007
Language: English
Type: text , Article
Identifier: vital:7087 , http://hdl.handle.net/10962/d1012415
Description: The principal activities of South African researchers in hydrology and water resources during the reporting period have been concerned with ground- and surface-water interactions, rainfall-runoff modelling, the establishment of improved regional water resource databases, the ecological Reserve, and investigating the likely consequences of climate change. Most of these studies have a strong emphasis on supporting the provisions of the National Water Act of 1998. Research programmes are benefiting from international and regional cooperation. In contrast, the lack of young scientists entering the field poses the greatest threat to hydrological research in South Africa.
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Date Issued: 2007

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The effect of physico-chemical parameters and chemical compounds on the activity of β-d-galactosidase (B-GAL), a marker enzyme for indicator microorganisms in water

- Wutor, V C, Togo, C A

Authors: Wutor, V C , Togo, C A
Date: 2007
Language: English
Type: text , Article
Identifier: vital:6470 , http://hdl.handle.net/10962/d1005800 , https://doi.org/10.1016/j.chemosphere.2007.02.050
Description: The presence of coliforms in polluted water was determined enzymatically (in situ) by directly monitoring the activity of beta-d-galactosidase (B-GAL) through the hydrolysis of the yellow chromogenic subtrate, chlorophenol red beta-d-galactopyranoside (CPRG), which produced a red chlorophenol red (CPR) product. The objectives of this study were to monitor the effect of compounds commonly found in the environment and used in water treatment on a B-GAL CPRG assay and to investigate the differences between the environmental B-GAL enzyme and the pure commercial enzyme. Environmental B-GAL was optimally active at pH 7.8. Two temperature optima were observed at 35 and 55 degrees C, respectively. B-GAL activity was strongly inhibited by silver and copper ions. While calcium and ferrous ions at lower concentrations (50-100mgl(-1)) increased the enzyme activity, a reduction was observed at higher concentrations (200mgl(-1)). Sodium hypochlorite, normally used in rural areas to disinfect water gradually decreased B-GAL activity at concentrations between 0 and 5600ppm for both the commercial and environmental enzymes. B-GAL from the environment behaved differently from its commercially available counterpart.
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Date Issued: 2007

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A Geographic Information System for the African Coelacanth Ecosystem Programme

- Scott, Lucy E P

Authors: Scott, Lucy E P
Date: 2006
Language: English
Type: Article
Identifier: vital:7129 , http://hdl.handle.net/10962/d1010639
Description: The African Coelacanth Ecosystem Programme (ACEP) Geographic Information System (GIS) has been developed to integrate, analyse and map all spatial data generated within the ACEP programme. A GIS is a multidisciplinary tool, and within ACEP the GIS has been used to integrate information from marine biology studies, oceanographic surveys, geophysical exploration as well as the observations made and footage taken from a research submersible. The core data in the GIS are based on deep marine ecosystems and the programme’s flagship species, Latimeria chalumnae (the coelacanth). Over and above the utility of the GIS as a tool for science through its considerable information storage, analysis and display capabilities, the ACEP GIS has been used for interactive environmental education purposes and to generate public awareness of the programme at various meetings, training events and conferences.
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Date Issued: 2006

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A Geographic Information System for the African Coelacanth Ecosystem Programme

- Scott, Lucy E P

Authors: Scott, Lucy E P
Date: 2006
Language: English
Type: Article
Identifier: vital:7159 , http://hdl.handle.net/10962/d1011886
Description: The African Coelacanth Ecosystem Programme (ACEP) Geographic Information System (GIS) has been developed to integrate, analyse and map all spatial data generated within the ACEP programme. A GIS is a multidisciplinary tool, and within ACEP the GIS has been used to integrate information from marine biology studies, oceanographic surveys, geophysical exploration as well as the observations made and footage taken from a research submersible. The core data in the GIS are based on deep marine ecosystems and the programme’s flagship species, Latimeria chalumnae (the coelacanth). Over and above the utility of the GIS as a tool for science through its considerable information storage, analysis and display capabilities, the ACEP GIS has been used for interactive environmental education purposes and to generate public awareness of the programme at various meetings, training events and conferences.
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Date Issued: 2006

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A new and earlier record of Chrysomya megacephala in South Africa, with notes on another exotic species, Calliphora vicina (Diptera Calliphoridae)

- Williams, Kirstin A, Villet, Martin H

Authors: Williams, Kirstin A , Villet, Martin H
Date: 2006
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/440710 , vital:73805 , https://hdl.handle.net/10520/EJC84554
Description: South African records of Chrysomya megacephala and Calliphora vicina are reviewed and plotted on maps. Dispersal routes of these two forensically and medically important blowfly species are discussed. Emphasised is the importance of deposition of voucher material in museum collections.
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Date Issued: 2006

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AmaNdebele, Peter Magubane and Sandra Klopper: book review

- Simbao, Ruth K

Authors: Simbao, Ruth K
Date: 2006
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/147336 , vital:38627 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31002
Description: AmaNdebele is a very attractive book with beautifully reproduced colour photographs taken by the renowned photographer Peter Magubane, who secured enormous credibility as a photojournalist during the violent years of apartheid. While some South African readers who browse through the glossy portrayals of ceremonial attire and homestead decorations may recall Magubane's earlier books such as Soweto speaks (1981) and Soweto: The fruit of fear (1986) in which the photographer laid bare the ferocious violence of apartheid rule, many readers will skip over the nuances of both Magubane's disrupted career and the contentious relationship between the Ndebele people and the South African apartheid government.
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Date Issued: 2006

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Doing the twist: a test of Darwin's cross-pollination hypothesis for pollinarium reconfiguration

- Peter, Craig I, Johnson, Steven D

Authors: Peter, Craig I , Johnson, Steven D
Date: 2006
Language: English
Type: Article
Identifier: vital:6534 , http://hdl.handle.net/10962/d1005975
Description: Mating success in plants depends largely on the efficiency of pollen dispersal. For hermaphrodite plants, self-pollination, either within or among flowers, can reduce mating opportunities because of pollen and ovule discounting and inbreeding depression. Self-pollination may be particularly detrimental in plants such as orchids and asclepiads that package each flower’s pollen into one or more pollinia which, together with accessory structures, comprise a pollinarium. Darwin proposed that physical reconfiguration of pollinaria serves as a mechanism for reducing the likelihood of self-pollination. To be effective, the time taken for pollinarium reconfiguration would need to exceed that spent by a pollinator on a plant. We investigated pollinarium reconfiguration (including pollinarium bending, pollinium shrinking and anther cap retention) in 19 species and found a strong positive relationship between reconfiguration time and the duration of pollinator visits. Reconfiguration times were also consistently longer than pollinator visit times. These results provide strong support for Darwin’s idea that this mechanism promotes cross-pollination. , Elsevier
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Date Issued: 2006

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Effects of prophylactic progesterone in decomposing tissues on the development of Chrysomya chloropyga (Wiedeman)(Diptera Calliphoridae)

- da Silva, C, Villet, Martin H

Authors: da Silva, C , Villet, Martin H
Date: 2006
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/442020 , vital:73950 , https://hdl.handle.net/10520/EJC32654
Description: Medico-legal forensic entomology is often concerned with the estimation of postmortem intervals (PMI), the time elapsed since the death of a body, by estimating the age of maggots if they are found on a body. These estimates can be complicated by the presence of a variety of drugs that may be present in dead bodies, including steroids such as hydrocortisone (Musvasva et al. 2001).
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Date Issued: 2006

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Inetvis, a visual tool for network telescope traffic analysis

- van Riel, Jean-Pierre, Irwin, Barry V W

Authors: van Riel, Jean-Pierre , Irwin, Barry V W
Date: 2006
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/430176 , vital:72671 , https://doi.org/10.1145/1108590.1108604
Description: This article illustrates the merits of visual analysis as it presents prelimi-nary findings using InetVis - an animated 3-D scatter plot visualization of network events. The concepts and features of InetVis are evaluated with reference to related work in the field. Tested against a network scanning tool, anticipated visual signs of port scanning and network mapping serve as a proof of concept. This research also unveils sub-stantial amounts of suspicious activity present in Internet traffic during August 2005, as captured by a class C network telescope. InetVis is found to have promising scalability whilst offering salient depictions of intrusive network activity.
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Date Issued: 2006

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Orthopaedic grade ultra–high molecular weight polyethylene: some features of the main thermoluminescence glow curve

- Chithambo, Makaiko L

Authors: Chithambo, Makaiko L
Date: 2006
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/125499 , vital:35789 , https://doi.10.1093/rpd/nci661
Description: Thermoluminescence (TL) characteristics of orthopaedic–grade ultra–high molecular weight polyethylene have been investigated between 20 and 200_C. The TL at 1_C s_1 consists of two glow curves, a weaker intensity peak at 115_C and the main peak at 70_C, studied in this work. TL intensity increases with beta irradiation but with a dose–response influenced by heating rate. On the other hand, the peak maximum is affected by both irradiation and repeated use of a sample. The glow curve shifts to higher temperatures with increase in heating rate but only slightly so with change in beta irradiation dose, properties suggestive of first-order kinetics. Kinetic analysis for activation energy and order of kinetics, based on the discrete trap model, produce somewhat conflicting results. Whereas qualitative analysis of peak symmetry show that first-order kinetics apply, geometrical analysis of the peak shape suggests that the order of kinetics might be other than first-order. Values of activation energy evaluated using the initial rise method were found to be dose dependent and for a given beta dose are in agreement with calculations from peak shape and initial rise methods but less so with results from variable heating rate method.
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Date Issued: 2006

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Variation in the timing of reproduction of the four-striped field mouse, Rhabdomys pumilio, in the Eastern Cape Province, South Africa

- Jackson, Claire, Bernard, Ric T F

Authors: Jackson, Claire , Bernard, Ric T F
Date: 2006
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/447101 , vital:74584 , https://doi.org/10.1080/15627020.2006.11407367
Description: We used the four-striped field mouse, Rhabdomys pumilio (Sparrmann, 1784), to test the hypothesis that reproduction in a small, short-lived mammal will be opportunistic, characterized by temporal and spatial variation in the timing of events, and only be inhibited under harsh and predictable winter conditions. Field mice were trapped for three years in two regions of the Eastern Cape Province of South Africa, one that experienced a predictable and harsh winter (Mountain Zebra National Park; MZNP) and the other which experienced a milder winter (Thomas Baines Nature Reserve; TBNR). There was no winter inhibition of reproduction at TBNR, while at MZNP female reproductive activity was inhibited but males continued to produce spermatozoa in winter. We interpret this flexibility in the timing of reproduction as supporting an opportunistic reproductive strategy which may be an adaptation to the seasonal and often unpredictable climate of the region.
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Date Issued: 2006

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